Tag Archives: American Contact Dermatitis Society

Here are the top five contact allergens that are missed using the standing 28-allergen screening tray (T.R.U.E. Test), according to Dr. Donald V. Belsito, who presented the top 25 at the annual meeting of the American Contact Dermatitist Society in San Diego. The results are based on a retrospective analysis including 2,088 patients who were patch tested from 1995-2010.

Drum roll please … the American Contact Dermatitis Society has named the antibiotic neomycin as Allergen of the Year for 2010.

Courtesy flickr user project 365 under common license

“It’s a very common allergen and raises a number of issues when someone patch tests positive to it. We thought it is something the general public and dermatologists should be aware of,” said Dr. Donald Belsito, a dermatologist in private practice in Shawnee, Kans., when making the announcement.

A positive patch test can take 7 days or more to develop, so have patients return or counsel them on what to look for, Dr. Belsito said.

He noted that there are a couple things to keep in mind when making the diagnosis of neomycin allergy.

First, many vaccines contain neomycin as a preservative. The risk to benefit considerations need to include the likely worst-case scenario–an eczematous rash–if a sensitive patient receives a vaccine containing neomycin. Contrast that with the likely worst-case scenario–contraction of a potentially lethal disease–if the sensitive patient avoids vaccination. Discuss. And don’t forget to bring the patient’s primary care doctor into the conversation, Dr. Belsito counseled.

Second, neomycin-sensitive patients can have cross reactivities to other aminoglycocides. Think kanamycin, tobramycin and others, said Dr. Belsito, who had no relevant financial disclosures.

Neomycin is more of a household name than last year’s Allergen of the Year, mixed dialkyl thioureas. My colleague Bruce Jancin described last year’s winner and patients’ reactions to it in a blog post one year ago.